V100R003 and previous versions: Combo interface The default type is optical port. V100R005 and later: That is, if the electrical port is inserted first, the preferred selective port is used as a data exchange interface. The multiplexed electrical and optical interfaces cannot work at the same time. You can use the electrical or optical interface according to. The Combo interface, also known as the optical-electrical multiplexing interface, consists of two Ethernet ports (one optical and one electrical) on the device panel, and there is only one forwarding interface inside the device. With regard to port. SR-LR: Stands for "short-range" and "long-range" optical modules, including other variants like LRM, ER, ZR, etc. For 1Gbps DAC, the appropriate link mode is 1G-baseX.